sylveos

commit 3fa4913f626e710efdffdc96c1ef24f99f86a32e
parent a7d5148aadd4989eb9827328c5a91260b8750d5d
Author: Sylvia Ivory <git@sivory.net>
Date:   Tue, 10 Feb 2026 21:23:37 -0800

Preserve all registers

Diffstat:
M
pi/interrupts.zig
 | 
6
++++--
M
programs/syscall.zig
 | 
2
++

2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/pi/interrupts.zig b/pi/interrupts.zig
@@ -109,7 +109,9 @@ var fast_interrupt_handler: *const fn (u32, *Registers) void = empty;
 
 pub const Registers = struct {
     gp: [13]usize,
+    sp: usize,
     lr: usize,
+    pc: usize,
 };
 
 export fn reset_stub(pc: u32, reg: *Registers) void {
@@ -139,12 +141,12 @@ fn create_trampoline(name: []const u8, offset: []const u8, ret: []const u8) []co
         ".global " ++ name ++ "\n" ++
         ".type " ++ name ++ ", %function\n" ++
         name ++ ":\n" ++
-        "  push {r0-r12, lr}\n" ++
+        "  push {r0-r15}\n" ++
         "  sub lr, lr, #" ++ offset ++ "\n" ++
         "  mov r0, lr\n" ++
         "  mov r1, sp\n" ++
         "  blx " ++ name ++ "_stub\n" ++
-        "  pop {r0-r12, lr}\n" ++ ret;
+        "  pop {r0-r14}\n" ++ ret;
 }
 
 comptime {
diff --git a/programs/syscall.zig b/programs/syscall.zig
@@ -36,7 +36,9 @@ noinline fn software_interrupt_handler(pc: u32, registers: *interrupts.Registers
     for (dup.gp, 0..dup.gp.len) |r, i| {
         uart.writer.print("r{d} = {d}\n", .{ i, r }) catch {};
     }
+    uart.writer.print("sp = 0x{X}\n", .{dup.sp}) catch {};
     uart.writer.print("lr = 0x{X}\n", .{dup.lr}) catch {};
+    uart.writer.print("pc = 0x{X}\n", .{dup.pc}) catch {};
     uart.toggle_tx_interrupts();
 }